The cape and the gown beneath it
A detachable cape can frame the shoulders, cover part of the back or extend behind the dress. Sheer material keeps more of the base gown visible; a textured or opaque layer can establish a stronger second outline. Length and attachment point decide where that change begins.
Texture or trailing length
Cascade adds a separate cape with specialty fabric, lace and dimensional feathers over a narrow sheath. Chantel layers a detachable long cape over a satin column, increasing the rear volume while its front line remains clear. The first cape brings surface texture to a minimal base; the second places a softer trailing layer against smooth satin.
A bolero offers a shorter upper-body layer if the emphasis should stay around the shoulders. For capes, compare the base gown with the added piece at a fitting so the neckline, back and attachment remain clear in both versions.